1、第六章 子程序結(jié)構(gòu) 過程定義偽操作 子程序的調(diào)用與返回 保存與恢復(fù)寄存器 子程序的參數(shù)傳送 子程序的嵌套與遞歸11. 過程定義偽操作 過程名 PROC NEAR ( FAR ) 過程名 ENDP（1）NEAR屬性：調(diào)用程序和子程序在同一代碼段中 （段內(nèi)調(diào)用）（2）FAR屬性：調(diào)用程序和子程序不在同一代碼段中 （段間調(diào)用）.2code segment main proc far call subr1 retmain endpsubr1 proc near retsubr1 endpcode endssegx segmentsubt proc far retsubt endp call subt

2、segx endssegy segment call far ptr subt segy ends3子程序調(diào)用：隱含使用堆棧保存返回地址 call near ptr subp (1) 保存返回地址 (2) 轉(zhuǎn)子程序 call far ptr subp (1) 保存返回地址 (2) 轉(zhuǎn)子程序子程序返回：ret2. 子程序的調(diào)用與返回 (SP) (IP)(IP)(CS)(SP)43. 保存與恢復(fù)寄存器subt proc far push ax push bx push cx push dx pop dx pop cx pop bx pop ax retsubt endp5(1) 通過寄存器傳送參數(shù)

3、(2) 通過存儲(chǔ)器傳送參數(shù)(3) 通過地址表傳送參數(shù)地址(4) 通過堆棧傳送參數(shù)或參數(shù)地址(5) 多個(gè)模塊之間的參數(shù)傳送4. 子程序的參數(shù)傳送6例：十六進(jìn)制到十進(jìn)制的轉(zhuǎn)換（通過寄存器傳送參數(shù)）hexidec segment ; 1610 assume cs: hexidec main proc farstart: push ds sub ax, ax push axrepeat: call hexibin ; 162 call crlf call binidec ; 210 call crlf jmp repeat retmain endphexidec ends end start7hexi

4、bin proc near mov bx, 0newchar: mov ah, 1 int 21h sub al, 30h jl exit cmp al, 10 jl add_to sub al, 27h cmp al, 0ah jl exit cmp al, 10h jge exitadd_to: mov cl, 4 shl bx, cl mov ah, 0 add bx, ax jmp newchar exit: rethexibin endpbinidec proc near mov cx, 10000d call dec_div mov cx, 1000d call dec_div m

5、ov cx, 100d call dec_div mov cx, 10d call dec_div mov cx, 1d call dec_div retbinidec endpdec_div proc near mov ax, bx mov dx, 0 div cx mov bx, dx mov dl, al add dl, 30h mov ah, 2 int 21h retdec_div endp 1 a b 5 31 61 62 358例：累加數(shù)組中的元素（通過存儲(chǔ)器傳送參數(shù)）data segment ary dw 1,2,3,4,5,6,7,8,9,10 count dw 10 sum

6、 dw ?data endscode segmentmain proc far assume cs:code,ds:data mov ax, data mov ds, ax call proadd mov ax,4c00h int 21hmain endpcode ends end mainproadd proc near push ax push cx push si lea si, ary mov cx, count xor ax, axnext: add ax, si add si, 2 loop next mov sum,ax pop si pop cx pop ax retproad

7、d endp9如果數(shù)據(jù)段定義如下：data segment ary dw 1,2,3,4,5,6,7,8,9,10 count dw 10 sum dw ? ary1 dw 10,20,30,40,50,60,70,80,90,100 count1 dw 10 sum1 dw ?data ends 如果直接訪問內(nèi)存變量，那么累加數(shù)組ary和數(shù)組ary1中的元素不能用同一個(gè)子程序 proadd。10例：累加數(shù)組中的元素（通過地址表傳送參數(shù)地址）data segment ary dw 10,20,30,40,50,60,70,80,90,100 count dw 10 sum dw ? table

8、 dw 3 dup (?) ; 地址表data endscode segmentmain proc far assume cs:code, ds:data push ds sub ax, ax push ax mov ax, data mov ds, ax mov table, offset ary mov table+2, offset count mov table+4, offset sum mov bx, offset table call proadd retmain endp 11proadd proc near push ax push cx push si push di mo

9、v si, bx mov di, bx+2 mov cx, di mov di, bx+4 xor ax, axnext: add ax, si add si, 2 loop next mov di,ax pop di pop si pop cx pop ax retproadd endpcode ends end main 30d 40d 50d 60d 70d 80d 90d100d 10d ary 20d 10dcountsumtable0000001400160018000000140016(bx)(si)(di)550d12例：累加數(shù)組中的元素（通過堆棧傳送參數(shù)地址）data seg

10、ment ary dw 10,20,30,40,50,60,70,80,90,100 count dw 10 sum dw ?data endsstack segment dw 100 dup (?) tos label wordstack ends13code1 segmentmain proc far assume cs:code1, ds:data, ss:stackstart: mov ax, stack mov ss, ax mov sp, offset tos mov ax, data mov ds, ax mov bx, offset ary push bx mov bx, of

11、fset count push bx mov bx, offset sum push bx call far ptr proadd mov ax, 4c00h int 21hmain endpcode1 ends14code2 segment assume cs:code2proadd proc far push bp mov bp, sp push ax push cx push si push di mov si,bp+0ah mov di,bp+8 mov cx,di mov di,bp+6code2 ends end start xor ax, axnext: add ax, si a

12、dd si, 2 loop next mov di,ax pop di pop si pop cx pop ax pop bp ret 6proadd endp(ip)(cs)sumcountarray (di) (si) (cx) (ax)(sp)(bp)(bp) (bp)+0ah (bp)+8 (bp)+6tos15多個(gè)模塊之間的參數(shù)傳送：局部符號(hào)：在本模塊中定義，在本模塊中引用的符號(hào)外部符號(hào)：在某一模塊中定義，在另一模塊中引用的符號(hào) PUBLIC 符號(hào) EXTRN 符號(hào):類型 extrn proadd : far code1 segmentstart: call far ptr proa

13、dd code1 ends end start; proadd1.asmpublic proadd code2 segmentproadd proc far retproadd endpcode2 ends end ; proadd2.asm16例：; proadd1.asmextrn proadd : fardata segment common ary dw 1,2,3,4,5,6,7,8,9,10 count dw 10 sum dw ?data endscode1 segment main proc far assume cs:code1, ds:datastart: mov ax,

14、data mov ds, ax call far ptr proadd mov ah, 4ch int 21hmain endpcode1 ends end start17; proadd2.asmpublic proadddata segment common ary dw 1,2,3,4,5,6,7,8,9,10 count dw 10 sum dw ?data endscode2 segment proadd proc far assume cs:code2,ds:data mov ax, data mov ds, ax push ax push cx push si lea si, a

15、ry mov cx, count xor ax, ax next: add ax, si add si, 2 loop next mov sum,ax pop si pop cx pop ax retproadd endpcode2 ends end18子程序的嵌套： 主程序 子程序A 子程序B遞歸子程序：n! n ( n - 1 ) ( n - 2 ) 1 3! 3 21= 65. 子程序的嵌套與遞歸調(diào)用 call proc_Aproc_A call proc_BCall proc_Aretproc_B ret19例：計(jì)算 n!frame struc save_bp dw ? save_cs

16、_ip dw 2 dup(?) n dw ? result_addr dw ?frame ends;data segment n_v dw 3 result dw ?data ends;stack segment dw 128 dup (?) tos label wordstack endsmov ax, bp . nmov bx, bp .result_addr 0!=1 n!=n(n-1)!20code segmentmain proc far assume cs:code, ds:data, ss:stackstart: mov ax, stack ；用戶堆棧地址 mov ss, ax

17、mov sp, offset tos push ds ；保存返回DOS地址 sub ax, ax push ax mov ax, data ；數(shù)據(jù)段地址 mov ds, ax mov bx, offset result ; 結(jié)構(gòu)數(shù)據(jù)入棧 push bx mov bx, n_v push bx call far ptr fact retmain endpcode ends21code1 segment assume cs:code1fact proc far push bp mov bp, sp push bx push ax mov bx, bp.result_addr mov ax, bp.

18、n cmp ax, 0 je done push bx dec ax push ax call far ptr fact mov bx, bp.result_addr mov ax, bx mul bp.n jmp short returndone: mov ax,1return: mov bx, ax pop ax pop bx pop bp ret 4fact endpcode1 ends (AX) (BX) (BP)CODE中的(IP)CODE中的(CS) 3RESULT的地址第1幀 (AX) (BX) (BP)CODE1中的(IP)CODE1中的(CS) 2RESULT的地址第2幀 (AX) (BX) (BP)CODE1中的(IP)CODE1中的(CS) 1RESULT的地址第3幀 (AX) (BX) (BP)CODE1中的(IP)CODE1中的(CS) 0RESULT的地址第4幀00FA00F200E400D600C8000000F200E400D622fact proc near push ax push bp mov bp, sp mov ax, bp+6 cmp ax, 0 jne fac